but many other possibilities exist. Depending on where we are in the cycle of
cancer–immune system interactions and on the actors of the tumor microenvir-
onment involved, some therapeutic strategies will aim at normalization while
others will aim at denormalization. Examples of normalization include the
reduction of the level of inflammation in the tissue, the elimination of pathogens
and/or chronic wounds, the restoration of immune accessibility to the tumor,
and the facilitation of the resolving phase of tissue repair. In contrast, denorma-
lization would be a major aim when the immune system interacts with tumor
components as if they were normal constituents of the body, as, for example,
when the immune system is tolerogenic in the context of chronically present
tumor antigens or when the immune system continuously triggers repair path-
ways to respond to a local cancerous context that displays many features usually
associated with a wound.
In summary, this section has shown that focusing on the immune system is
essential for anyone studying cancer. Cancer is a disease of multicellularity
and, more specifically, of the cohesion of the multicellular organism.
Immunological surveillance constitutes one of the main and best described
mechanisms by which the multicellular organism exerts control over lower-
level entities. A major result of recent research is that the immune system can
both restrain and promote cancerous tumors, which may seem, atfirst sight,
paradoxical. Yet the situation becomes less paradoxical when one realizes that
immune-mediated decohesion is often due to an abnormal context rather than
a dysfunctional immune system. We have suggested here an extended view of
cancer–immune interactions, which opens up many opportunities for investi-
gating new mechanisms of tumor control and tumor promotion and, ulti-
mately, for developing novel therapeutic opportunities based on the action
oftheimmunesystem.
5 Neuroimmunology: The Intimate Dialogue between
the Nervous System and the Immune System
Whatever forces were operating to set immunology apart, recent data suggest that
much could be learned by studying immunoregulation as part of an integrated
network of adaptive processes including behaviour. If not now, when? (Ader and
Cohen 1985)
These exciting revelations place neuroimmunology at the forefront of biomedi-
cal research priorities. With the potential to affect such a diverse array of neuro-
logical ailments, many of which have no known therapy, the hope is that an
improved understanding of immune-CNS interactions will bring to light new
paradigms for preventing and treating neurological disease. (Mueller et al. 2016)
Thesefindings suggest that the brain–cytokine system, which is in essence
a diffuse system, is the unsuspected conductor of the ensemble of neuronal circuitsPhilosophy of Immunology 43